Locksets, including leversets, are commonly installed on hinged barriers including but not limited to doors and gates. Their ease of installation contribute to their popularity. There are some aspects of locksets, however, that are less than ideal.
A lockset may be bought having a predetermined lockset function that determines how a user interacts with the lockset. Generally, in each family of locksets there are only a limited number of ways of a user operating the a latch bolt, but numerous ways of preventing the user from operating the lockset's latch bolt. Some example functions known to locksmiths include:                entrance        vestibule        double vestibule        classroom        glass door        patio        privacy        passage        
These functions are summarised in the table in FIG. 1. Currently, a single lockset may not be able to perform more than one function. Consequently, a locksmith may need to hold different locksets that have different functions. This requires the holding of more locksets then desirable, requiring significant amounts of capital and greater storage requirements. A locksmith may not have the space in his vehicle to carry different types of locksets and may be caught out without a lockset having the required function. It may not be possible to change the function of a lockset once installed, which would need replacing if a different function was required.